This invention relates to laser machining of molded assemblies.
The operating temperature of an electronic component, relative to the temperature of a heat sinking medium, depends upon the amount of heat generated by the component and the thermal conductivities of the paths between the component and the heat sinking medium. For example, FIG. 1 shows an exploded view of a DC-DC converter module or modular power converter 100 which includes an overmolded control assembly 44 (see, for example, "Power Converter Configuration, Control and Construction," U.S. patent application Ser. No. 08/077,011, filed Jun. 17, 1993, and "Packaging Electrical Components," U.S. Pat. No. 5,365,403, both incorporated herein by reference). A metallic baseplate 52 is provided for removing heat from the assembly. Metal shields 27, which are tightly thermally coupled to, but electrically insulated from, the baseplate 52, serve to reduce the thermal resistance between power dissipating components 66 and the baseplate (see "Packaging Electrical Components," U.S. patent application Ser. No. 08/337,269, filed Nov. 10, 1994, incorporated herein by reference). When assembled, the interior of the module is filled with an encapsulating material which helps to conduct heat from other internal components to the baseplate. In such an assembly, the operating temperature of heat dissipating components within the control assembly 44 will depend upon the thermal conductivities of the paths between the components and the baseplate.
One way to reduce the temperature differential between a heat sinking surface and a heat dissipating component is to provide a conductive metal path between the heatsink and the component.